A large number of indicators, dosimeters, monitors, detectors, sensors and the like, especially those which undergo a change in color or fluorescence, are developed for monitoring presence and concentration of variety of materials, such as toxic chemicals and processes, such as sterilization of medical supplies with steam. This type of indicators, dosimeters, monitors, sensors, detectors and the like, individually or collectively, are referred herein as indicator(s) or dosimeter(s).
Many patents have been issued on color changing indicators, monitors, detectors, and dosimeters for monitoring a variety of processes and materials. They include indicators for chemicals, pH, sterilization, humidity/moisture, time, time-temperature, temperature and radiation. Many of these indicators are available commercially. Some representative examples of recent patents include: freeze indicators in U.S. Pat. No. 6,472,214 to Patel; hydrogen peroxide indicator in U.S. Pat. No. 6,267,242 to Nagata et al.; carbon dioxide indicators in U.S. Pat. No. 6,436,347 to Cedeon and U.S. Pat. No. 5,849,594 to Balderson et al.; aldehyde strip indicators in U.S. Pat. No. 6,436,716; toxin indicators in U.S. Pat. No. 6,361,962 to Lentini et al.; ozone indicators in U.S. Pat. No. 6,336,964 Omatsu et al.; temperature indicators in U.S. Pat. No. 6,176,197 to Thompson; sterilization indicators in U.S. Pat. No. 5,916,816; breath, air and gas vapor indicators in U.S. Pat. No. 5,834,626 to De Castro et al.; biological indicators in U.S. Pat. No. 5,770,393 to Dalmasso et al.; fat and moisture indicators in U.S. Pat. No. 5,433,214 to Brehm et al.; time-temperature indicator in U.S. Pat. No. 6,435,128 to Qiu et al.; UV radiation indicator in U.S. Pat. No. 6,504,161 to Jackson et al, and high energy indicators, such as X-radiation, in U.S. Pat. No. 6,504,161 to Jackson et al.
Reagent test strips are widely used in clinical chemistry. Usually, this analysis involves a color comparison between the reacted test pad/strip and a color standard or scale. In this way, reagent test strips assist physicians in diagnosing the existence of diseases and other health problems.
Reflected or transmitted light comparisons made with the naked eye can lead to imprecise measurement. Instruments, such as optical densitometers and spectrophotometers can be employed for reading the indicators. These instruments determine the color change of the indicator, but only with limited resolution and precision. This is mainly because optical density or spectra are recorded only of a small area of the strip/dosimeter. For higher accuracy, the whole area of the indicator should be monitored. This can be best done by using a scanning device, such as CCD (charge-coupled device) camera. There is no report on use of CCD camera or an optical scanner for reading the dosimeter and determining the treatment condition by comparing with a series of images of pre-treated dosimeter stored in a computer.
Scanning devices, such as a CCD camera, are used for identification of people by recording their finger prints, faces and iris and comparing the scanned images with those stored in the database. There is no report on the use of similar system for reading the dosimeter and determining the treatment condition by comparing with a series of images of pre-treated dosimeter using software.
Bar codes are used in a wide variety of applications for retrieving information, such as the price of an object. In this respect, bar code scanners are of widespread use in grocery stores and department stores, for both inventory control and for point-of-sale transactions.
A bar code normally includes several bar code characters. A bar code character is a group of lines (bars) and spacings that represent a single number or letter. A bar code symbol is a collection of several bar code characters which represent an identification of a particular object. The lines of the bar code can vary, for example, in a range from about ⅛″ to 1″ in height, and from about 1 to 50 mils in thickness. The spacings between the lines of the bar code symbol may be of various widths, with the variations in the spacing being one indication of the type of bar code characters making up the bar code symbol.
Bar codes are scanned to transform the graphic symbol elements into electrical signals, which are then decoded into characters. A scanning system uses a light source, typically a laser, which is directed to the symbol or bar code by a lens or other optical components. The scanner functions by repetitively scanning the light beam in a path or series of paths across the symbol. Scanning systems also include a sensor or photodetector which detects light reflected from the symbol. A portion of the reflected light is detected and converted into an electrical signal, and electronic circuitry or software decodes the electrical signal into a digital representation. The symbol is decoded according to the coding technique used, e.g., the Uniform Product Code (UPC) on many supermarket items.
Another conventional method for collecting return light from the bar code label is by the use of an array (commonly known as a charge-coupled device or CCD) of optical detectors connected to an analog shift register. In such a method, as with a scanning laser, an electrical signal is generated having amplitude determined by the intensity of the collected light. In either the scanning laser method or the CCD method, the amplitude of the electrical signal has one level for dark bars and another level for light spaces. As the bar code label is scanned, positive-going and negative-going transitions in the electrical signal occur, signifying transitions between bars and spaces. Techniques are known for detecting edges of bars and spaces by detecting the transitions of the electrical signal. One such technique is described in U.S. Pat. No. 5,382,783, issued to Edward Bremer. Other techniques are described in U.S. Pat. No. 5,298,728, to Randy Elliott et al. Techniques are also known for determining the widths of bars and spaces based on the relative location of the detected edges and decoding the information represented by the bar code.
U.S. Pat. No. 5,637,876 describes a radiation dosimeter, which is exemplary for use in determining a level of radiation to which a patient is subjected during radiation treatment, which comprises a substrate provided with a layer of radiation sensitive material. The radiation sensitive material has an optical density which varies systematically in accordance with the degree of radiation exposure. The dosimeter may take the form of a card or a flexible substrate which is positionable on the patient or other irradiation subject and which is also positionable in, or slidable through a slot in, a dose reader which includes a reflection or transmission densitometer.
A fiber optic diffuse light reflectance sensor is disclosed in U.S. Pat. No. 5,701,181 to Boiarski et al. The sensor employs illumination optical fibers to carry light emitted from a high-intensity, narrow bandwidth LED to a baffle in a readhead where the optical fibers reflect the light off of a reagent test strip. The illumination optical fibers are randomly oriented to create a more uniform light source. The light is reflected off of a pad on a reagent test strip to detect the presence of non-hemolyzed trace and hemolyzed occult blood. The reflected light must pass through another baffle to a bi-convex lens where it is focused onto a detection bundle of optical fibers. The detection bundle is optically coupled with a CCD, where the optical signal is converted to an electrical one for processing and analysis.
A method and associated apparatus for monitoring exposure to radiation, with compensation for temperature variation of a sensor and variations in the amount of radiation sensitive material in a dosimeter used in the method is disclosed in U.S. Pat. No. 6,285,031 to Carl Listl. The method utilizes a radiation dosimeter having a layer of radiation sensitive material on a substrate, the radiation sensitive material having an optical absorbance which varies in accordance with degree of radiation exposure and wavelength and which also varies in dependence on temperature. The method comprises exposing the layer of radiation sensitive material to a dose of radiation, optically measuring a spectral absorbance of the exposed layer of radiation sensitive material within a range of wavelengths, examining the measured spectral absorbance of the exposed layer of radiation sensitive material to determine an absorbance coordinate and a wavelength coordinate of a predetermined point on a spectral absorbance curve of the exposed layer of radiation sensitive material, and determining a radiation dose value associated with the absorbance coordinate and the wavelength coordinate. Generally, the radiation dose value is determined by consulting a table of absorbance and wavelength coordinates with associated dose values which have been previously measured for a batch of the radiation sensitive material, the batch having a uniform absorbance coefficient and a common concentration of the radiation sensitive material. The method can automatically compensate for variations in the amount of radiation sensitive material by adjusting the absorbance value of the radiation sensitive material by a measured value of absorbance in the radiation impervious substance.
A bar code scanning system for a conveyor system, including a CCD camera, that writes data to a memory is disclosed in U.S. Pat. No. 6,296,187 to Franks Shearer. Data is stored in the memory as a two-dimensional image at periodic time frames based on scanning by the CCD camera. Data is written out of the memory by a controller to create a virtual X-scan pattern that can be read and decoded by a decoder that is configured to decode X-scan patterns. Alternatively, the memory can be configured as a first memory region for receiving even pixel data and a second memory region for receiving odd pixel data.
U.S. Pat. No. 6,810,137 to Jones et al discloses a document processing system comprising an input receptacle for receiving documents. A transport mechanism receives the documents from the input receptacle and transports the documents past a full image scanner and a discrimination unit. An output receptacle receives the documents from the transport mechanism after being transported past the full image scanner and the discrimination unit. The full image scanner includes a means for obtaining a full video image of the documents, a means for obtaining an image of a selected area of the documents, and a means for obtaining information contained in the selected area of the document. The discrimination unit includes a means for determining the authenticity of the document. A system controller directs the flows of documents over the transport mechanism.
U.S. Pat. No. 6,803,956 describes a color-recognition camera comprising a red-green-blue CCD-imaging device that provides an analog RGB-video signal. A set of three analog-to-digital converters convert the analog RGB-video signal into a digital RGB-video signal. A digital comparator tests the digital RGB-video signal pixel-by-pixel for a match against a color setpoint. If a match occurs, a pixel with a particular color represented by the color setpoint has been recognized and a “hit” is output. A pixel address counter provides a pixel address output each time a “hit” is registered. The number of hits per video frame are accumulated, and a color-match area magnitude value is output for each frame. Alternatively, neural networks are used to indicate hits when a pixel in the video image comes close enough to the color setpoint value. Just how close can be “learned” by the neural network.
A reader for monitoring color change of a dipstick is disclosed in CA 2,223,671. A reader is either a computer controlled or a stand-alone instrument. The reader uses a CCD (charge-coupled device) camera to capture the image for processing. The reader uses computer or stand alone chips for digital image processing. The reader can read dipstick format, cassette format, and other membrane based formats as well as ELISA format diagnostic test kits. Modes can be selected for different test format and types of tests. The reader can read one test or multiple tests at a time. The image handling procedures of the reader are as following: (a) the test kit(s) is/are placed on the reading window; (b) digital image(s) will be taken by one or more CCD camera(s); (c) computer or microprocessor will manipulate the image; (d) the color intensity and location of a marker on the test will be recorded; (e)clinical results will be calculated based on the preset formulators and (f) hard copy results will be print out by printer.
A method for creating a volumetric data set representing a three-dimensional distribution, such as a dose distribution produced by a radiosurgery system, using a plurality of stacked sensors to obtain two-dimensional cross sectional images of the distribution is disclosed in U.S. Pat. No. 6,826,313 to Robar et al. The images are optically scanned in a scanner to obtain digitized two-dimensional images which can be processed by software. Each of the sensors, which may be, for example, a sheet of X-ray sensitive film, is marked with a visible fiducial mark. The software locates images of the fiducial marks in the digitized images. The locations of the fiducial marks indicate the proper orientation and sequence of each image. The software populates a volumetric data structure with data from the scanned images. Interpolation may be used to increase the resolution of the data structure. The system is not susceptible to errors which might be caused by images of the sensors being inverted or mis-aligned before or during scanning.
U.S. Pat. No. 6,770,487 to Crosby discloses diagnostic test devices, including diagnostic strip tests, in which identifying information and the test result are machine-readable. Also provided are methods for obtaining identifying information and test results from the diagnostic test devices.
U.S. Pat. No. 6,717,154 to Black et al. discloses methods for quantifying the irradiation dose received by an item or items, such as food items and medical items, undergoing irradiation-based sterilization. Included is the step of monitoring a selected electronic parameter associated with an economic single use sensor positioned adjacent the item or items and telemetrically relaying data associated with the monitored electronic parameter to a computer. The computer includes a computer program which is configured to determine the radiation dose received by the item or items by correlating the value of the monitored electronic parameter to a corresponding amount of radiation associated with the value. Related sensors and systems are also described.
U.S. Pat. No. 6,716,393 to Lappe et al. describes a system for automatically testing a fluid specimen, e.g., urine, to indicate the presence of specified chemical components in the specimen. The system preferably utilizes an assaying device comprised of a collection cup and a cap which carries at least one test strip. The device includes an integrated aliquot delivery mechanism actuatable to wet the test strip with an aliquot delivered from the fluid specimen. The assaying device is configured to operate in conjunction with an electronic reader device capable of actuating the aliquot delivery mechanism and reading the reaction of the test strip. A preferred reader device defines a keyed receptacle for accommodating a complimentary shaped cup housing in a particular orientation. The reader device is comprised of a camera for capturing the image of a test strip, an actuator for actuating an aliquot delivery mechanism, and a microprocessor/controller for controlling the camera and actuator and for processing the image.
U.S. Pat. No. 6,713,298 to McDevitt et al. describes a system for the rapid characterization of multi-analyte fluids including a light source, a sensor array, and a detector. The sensor array is formed from a supporting member into which a plurality of cavities may be formed. A series of chemically sensitive particles are positioned within the cavities. The particles may be configured to produce a signal when a receptor coupled to the particle interacts with the analyte. Using pattern recognition techniques, the analytes within a multi-analyte fluid may be characterized.
U.S. Pat. No. 6,685,094 to Cameron discloses a bar code incorporating thermochromic materials in selected modules such that its code changes with temperature. Below a specified temperature, the bar code displays a first code. Above this temperature, the bar code displays a second code. The bar code is printed with conventional printing equipment onto conventional printing media, and is scanned with conventional bar code scanning equipment.
U.S. Pat. No. 6,545,705 to Sigel et al. discloses a line scan digital camera directed at a station for recording and displaying a time-sequential scene. The digital camera takes a sequence of digital image frames representative of one or more bodies crossing a plane in space, wherein each frame represents a line image of the body, thus forming a fractional part of the scene, and the set of time-successive frames forms a recognizable image on an external display. Within the camera, frames enter a buffer and a microprocessor in the camera compares blocks from successive line images to detect changes indicative of objects entering or leaving the field of view. The changes detected by pixel or block analysis identify information-containing portions of the data stream and their time of occurrence. When the start or end of an object is detected the microprocessor flags the image stream with the detected data to produce an image data stream which can be more readily received and used by the external race management system, or the processor operates a controller in the camera which passes the active portion of the image information data stream to the output port, producing a more compact data stream with no loss of information.
U.S. Pat. No. 6,488,890 to Kirckof discloses a sterilization indicator having sterilizing agent sensitive indicia. The indicator allows a sterilization cycle to be monitored without the need for a user to subjectively distinguish between color, quality or intensity of display patterns.
U.S. Pat. No. 5,408,535 to Howard, III et al. describes a video test strip reader using a video imager or camera for viewing a viewing field containing reagent test strips each having test pads reacted with a specimen containing constituents of interest. The video imager produces an analog signal representing an image of the viewing field. An image handler coupled to the video imager converts or digitizes the analog signal into a digital signal representing the image and stores the image in the form of an array of pixels representing the image. Each pixel contains color information broken down into red, green or blue (RGB). A processor coupled to the image handler analyzes the array of pixels, determines the location and orientation of a test strip, identifies the test areas on the test strip, measures the corresponding test areas on the strip at the proper times and calculates the test results, such as the concentration of the constituents of interest in the specimen or other measurable properties of the specimen, such as color or specific gravity, etc. Accordingly, the video test strip reader can simultaneously locate, color analyze and time track multiple test strips on the viewing field.
In spite of the myriad of test procedures the art still lacks a general purpose high accuracy dosimeter reader for determination of a treatment condition, based on comparison of an image of treated dosimeter with a series of images of pre-treated dosimeter. The art also lacks a dosimeter device which changes color upon treatment with certain materials, such as toxic gases and processes, ionizing radiation and sterilization is pre-treated, imaged with an imaging device, such as CCD camera and images of the dosimeter or the changes, e.g., color change, are stored in an information storage device and where a treatment condition is determined by comparing an image of treated dosimeter with a series of pre-treated images of the dosimeter using a software.